Control device



May 16 1961 H. v. ELLIOTT ETAL 2,984,804

CONTROL DEVICE Original Filed Nov. 13, 1956 2 Sheets-Sheet 1 Z0 u T 4 5%v'* Z Z I z 5 3d 5' 52 34 JNVENToRs 3? /q/oLo L/ZUOTT F 5 B JOE CHA/H047ff P.

May 16, 1961 H. v. ELLIOTT x-:rAL 2,984,804

CONTROL DEVICE Original Filed Nov. 13, 1956 2 Sheets-Sheet 2 Fig. 7

INVENToRs Harold V Elliott By Joe R.Canaday Their A Homey United StatesPatent @hice CONTROL DEVICE Original application Nov. 13, 1956, Ser. No.621,578,

now Patent No. 2,942,220, dated June 21, 1960. Di-

vided and this application Sept. 25, 1959, Ser. No.

4 Claims. (Cl. SSS- 159) This invention relates to control devices andis more particularly concerned with an improved switch structure that isadapted to control the lighting circuits in an automotive vehicle. Thisis a divisional application of co pending parent application S.N.621,578, led November 13, 1956.

It has been found that when rheostat control means are included inswitches of the type herein contemplated, such as disclosed inapplication Serial No. 457,740, filed September 22, 1954, now Patent2,779,827, which has been assigned to the assignee of the presentinvention, high temperatures are frequently generated in the resistanceunit. These high temperatures may cause oxidation of the resistanceelement and deformation of certain of the switch parts particularly ifthe parts are formed of a super .linear polyamide commonly known asnylon. Therefore, basically, the present invention is directed toeliminate the effects of heating on the switch parts and to provide aswitch structure which is easier to assemble and wherein theobjectionable rattles of certain of the switch parts are eliminated.

It is an object of the present invention to provide a switch structurewherein a recess in a switch housing of molded dielectric material isclosed by a base for the switch which has bails located thereon, whichbails will hold the base and housing assembled after the bails are bentover lugs in the housing.

A further object of ythe present invention is to actuate the variouselements of a switch with a single rod that is both longitudinally androtatively movable and has a rectilinear cross section and to preventlthe rod from vibrating by a means including a bushing that is providedwith a nylon insert sized to snugly engage the angular edges of therectilinear rod. In this connection it is tto be pointed out that theactuating rod is preferably triangular in cross section, which shapewill provide three apexes longitudinally extending along the sides ofthe rod. These apeXes are preferably slightly rounded to avoid cuttingthe nylon part, which has a bore sized to tightly engage the apexes.Further, as will be hereinafter apparent, the bore of the nylon partwhich is initially circular is changed in shape after the rod ispositioned therein. The nylon being wear resistant and resilient willdeform to receive the apeXes of the rod and snugly maintain the rod fromvibrating.

A still further object of the present invention is to provide a switchwith a sliding contact and actuating means therefor wherein the slidingContact is formed of a single piece of metal having a center openingwith a projection on one side of the opening arranged to slide upon anannular metal element and is provided with a pair of projections on theopposite side of the opening, which engage an annular resistanceelement. Thus, the metal part will have a three point suspension and bespaced from the annular elements so air may circulate over heatradiating and conducting means or fms which are formed on the peripheryof the metal part.

Patented May 16, 1961 This will permit the heat generated in theresistance element to be dissipated. 'I'he switch is further provided.with an actuating means which includes a nylon part and a rod oftriangular cross section which is rotatable to actuate the nylon part.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

Fig. l is a side view of the switch incorporating the features of thepresent invention.

Fig. 2 is a sectional view taken along line 2 2 in Fig. l.

Fig. 3 is a sectional view taken along line 3--3 in Fig. 2.

Fig. 4 is a view taken along line 4 4 in Fig. 1.

Fig. 5 is a view showing in section a part of the switch along line 5 5in Fig. l.

Fig. 6 is an exploded view of a portion of the switch illustrated inFig. l.

Fig. 7 is a sectional view taken along line 7-7 of Fig. 6.

In the drawings and in Fig. l particularly, the numeral 2li designates aswitch which has a switch housing 22, preferably formed of a moldedphenolic resin with a filler. The housing 22 is supported by the base24. The base 24 and housing 22 are clearly shown and described in detailin the application supra wherein it is pointed out that the housing 22has a recess containing various switch elements which are actuated bythe longitudinal movement of the actuating rod 26. Molded to the bottomsurface 2S of the housing 22 are a pair of lugs 30. These lugs arelocated to receive suitably located openings in the base 24 to locatethe base 24 and housing 22 in proper position during assembly wherebythe recess in the housing is closed. Also, integrally formed on thesidewalls of the housing are four spaced lugs 32. These lugs 32 arelocated on the opposite sidewalls of the housing 22 along the bottomsurface 28. One of these lugs is most clearly shown in Fig. 5. Extendingfrom the periphery of the base 24 are four bails 34, which are formed asshown in Fig. l and located to be bent over the lugs 32, as shown inFig. 5, for securing the housing 22 and base 24 together.

The switch 2i) also includes a second switch means 36, which is actuatedby the rotational-movement of rod 26. This second switch means 36 isassembled with the switch housing 22 and base 24, as set forth in theapplication supra. The second switch means 36 includes a part 3S,preferably formed of a dielectric material that is highly heatresistant. The part 38 is formed with a recess 39, which is generallyannular in shape to receive a coiled resistor 40, which is electricallyconnected, as set forth in Patent 2,779,827 supra. The part 36 also hasa central opening which is aligned with an opening in housing 22 and theopening 42 in base 24. The opening in part 38 is preferably surroundedwith a metal annulus 41, the purpose of which will become hereinafterapparent.

The switch means 36 includes a member 44, most clearly shown in Fig. 4.The member 44 is preferably formed of a single metal part to have acircular shape. This member 44 has a central opening 46, which ispreferably non-circular in shape as shown. Located adjacent the openingand projecting from one surface of the member 44 is a lug or projection48. This projection is adapted to ride on the inner annular member 41carried in the opening in part 36. Disposed on the opposite side seasonVsame surface of member 44 from which lug 43 projects. .The lugs 5i) and51 are located to engage the coiled resistor 4% to complete anelectriccircuit between the inner annulus 41 and the coiled resistor 4b. Thecoiled resistor 4t) acts as a rheostat element to vary the current iiowin the manner well known to those skilled in the art.

The member' 44 is constantly urged into contact with the coil resistor4t) and the inner metal annulus 41 by the spring 52. When the parts ofthe switch are thus positioned, a threepoint suspension is provided forthe member 44. The coiled spring 52 rests on a shoulder on the vpart 54which is preferably formed of a molded material, such as a super linearpolyamide, commonly known as nylon. This .part 54 has a pair of lugs 56and 53. The lug 56 is arranged to actuate a dome light switch, as setforth in Patent 2,779,827 supra and the lug 58 is located to engage astop, not shown, which is formed on the base 24 to limit the rotationalmovement of the rod 26. The part 54 is preferably formed with a triangularly shaped central opening 6i) which receives the rod 26. Thepartr54 also has a projecting part bil, which is surrounded by thecoiled spring 52 and which has a shape corresponding to the opening 46in part 44 so as to provide a driving connection for the part 44 whenthe rod 26 is rotated. The part 54 is positioned between the part 44 andthe turned up portion of the base 2.4. The end of part 54 adjacent thepart 24 has an enlarged bore 62, which receives an inwardly turnedthreaded ange 64 on the base Z4 to maintain the part 54 in position.Threaded into the opening in base 24, which is deiined by the inwardly-threaded flange 64, is a mounting and anti-rattle means which includesa bushing 66. This bushing has a threaded portion 68 receivable in thethreaded opening 64 and a bore 69. Positioned in bore 6g is ananti-rattle means consisting of a nylon part 70. The nylon part 70` issecured in the bore 69 in any suitable manner and has a central bore 72which is sized to tightly receive the apexes 74 of the triangular rod26. Preferably, the bore 72 is of a size so that the nylon material ofthe part l72 will be slightly stretched and deformed from its normallycircular shape to prevent vib-ration in the rod 26. The actuating rod 26has a knob '78 secured thereto in any suitable fashion.

Manifestly, the rod 26 may be other than triangular in cross sectionalshape, as shown, as for example, it

Vmay be rectangular or have any other rectilinear configuration providedthe, rod will have longitudinally extending apexes projecting from thesurface which are in tight engagement with the nylon part. Also, theapexes 74 are preferably rounded to minimize wear of the nylon part whenthe rod is moved either longitudinally or rotatably.

includedon part 44 are a plurality of radially extending fins or fingersS3. These lingers Vare integrally formed on the part 44 and extend, asshown, so as to dissipate the heat created in the coiled resistor 4bwhen current passes therethrough. As heretofore stated, eect of the heatin the resistance 4b is detrimental to various parts of the switch andfrequently causes oxidation of the coiled resistor so an improperelectrical contact occurs with the member 44. Further, heat will alsocause softening of lthe nylon parts of the switch. n

The switch according to the present invention by having the tins 53spaced from the coil 4G by the three point suspension provided by lugs4%, 5@ and 5l will have an eiiicient heat dissipating means. Further,the

use of a rectilinear rod rather than a circular rod as a rotationaldriving means will cause a more positive drive even though the nylonparts are softened because of heat.

While the embodiment ofthe present invention as herein disclosedconstitutes a preferred form, it is to be understood thatjother formsmight be adopted.

What is claimed is as follows:

V1. An electrical control device comprising, a base member, a rstinsulator member formed of insulating material supported b said basemember, a length of resistance material having an annular shapesupported by Vsaid tirstinsulator member, an annular metal contact stripsupported by said ltirst insulator member and radially spaced yfrom saidlength of resistance material, a bridging contactV memberformed ofelectrically conductive material, said contact member having first andsecond integral projecting portions contactinfj respectively said lengthoff Vresistance material and said annular contact strip, said contactmember further having heat radiating tin means, 4a second insulatormember formed of insulating material and rotatable with respect to saidbase, means drivably connecting said second insulator member and saidcontact member whereby they rotate together, and spring means positionedbetween said second insulator member and said contact member for urgingsaid contact member toward said length of resistance material and saidannular contact strip.

2. An electrical control device comprising, an insulator member formedof insulating material, a length of resistance material having anannular configuration supported by said insulator member, an annularmetal contact strip supported by said insulator member and spaced fromsaid length of resistance material, a bridging contact member formed o'felectrically conductive material and having 'lirst and second integralprojecting portions contacting respectively said length of resistancematerial and said annular contact strip, said bridging contact memberhaving heat radiating fin means, manually operable means for rotatablyldriving said bridging contact member, and means for urging said bridgingcontact member toward said resistance material and said annular contactstrip.

3. An electrical control device comprising, an insulator member formedof insulating material, a length of resistance material having anannular configuration supported by said insulator member, an annularmetal contact strip supported by said insulator member and spaced fromsaid length of resistance material, a bridging contact member `formed ofelectrically conductive material and having tiret, second and thirdintegral projecting portions contacting respectively said length otresistance material and said annular contact strip, said bridgingcontact member having heat radiating tin means, manually operable meansfor rotatably driving said bridging contact member, and means for urgingsaid bridging contact `member toward said resistance material and saidannular contact strip.

4. The control device according to claim 3 wherein the outer edge of thebridging co'ntact member is formed with alternate notches defining theheat radiating iin means.

References Cited in the le of this patent UNITED STATES PATENTS 633,172Wirt Sept. i9, 1899 2,201,686 Marsten May 21, 1940 2,204,623 Ruben June18, 1940 2,807,680 Brown et al. Sept. 24. 1957

